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Ponca City, We love you writes "Jet packs have been around for half a century, but there's always been one problem: they run out of fuel in around 30 seconds. Now a German company has taken the standard jet pack design, run a fat yellow hose out the back, and connected it to a small unmanned boat that houses an engine, pump, and fuel tank and sends pressurized water up the hose, where it's shot out by two nozzles just behind the wearer's shoulders. Called the JetLev-Flyer, the design purportedly can reach a height of 15 meters, a speed of 72 kph, and a range of 300 kilometers based on four hours of flying time. A digital fly-by-wire system is used to control the throttle. Future designs may achieve higher altitudes, higher top speeds, and extended range, and even travel below the water's surface. The American manufacturers claim it is 'amazingly easy to learn and operate' and they're taking orders now at $130,000 each."

The boat is towed along behind the jetpack, so the range is correct, if you are only flying above water:)Which limits the practicality in my mind. If however they can engineer them to work underwater, with a longer hose like those used on old diving suits, then I can see this having a purpose, i.e faster descent times and time spent examining shipwrecks etc.

lol; I think they mean the boat / pump thing will be underwater, not the jetpack. Divers are limited by physiological things when ascending and descending, not how fast they can swim. SCUBA certification organizations will tell you one foot per second up and down is about the limit. They already have underwater propulsion things (little units you hang on to that you point in the direction you want to go, and they run of batteries) to combat currents, long distance requirements, etc. that are about as good as required.

This seems more of a limit on a jetpack than I'd be willing to accept. I mean, cruising along 100 feet over the ground (Well, the water) is fine until you hit a dock, or accidentally go over land. Then you've got 100 feet of free-fall.

As a bonus, you're almost guaranteed for this thing to ONLY fail when you're NOT over water, eliminating the only chance you have of surviving that big of a fall.

This seems more of a limit on a jetpack than I'd be willing to accept. I mean, cruising along 100 feet over the ground (Well, the water) is fine until you hit a dock, or accidentally go over land. Then you've got 100 feet of free-fall.

As a bonus, you're almost guaranteed for this thing to ONLY fail when you're NOT over water, eliminating the only chance you have of surviving that big of a fall.

Right! Just like a jet-ski, boat or any other water craft tends to fail when pulled out of the water. Well, except on a jet-ski, you impact the pier at 50 mph whereas with this thing, you your jets fail and you fall on to the pier or bank. There is no mention of how this thing operates when it's pulled out of the water. The jets may die all at once, causing you to free-fall, or the pressure may drop over a few seconds, giving you are much softer landing.

I can see this having a purpose, i.e faster descent times and time spent examining shipwrecks etc.

Come back when you get certified for SCUBA. The rate of descent is limited by how fast you can equalize your ears (which is about 1 m/s), and the rate of ascent by how your tissues are de-gassing, which has to be slower than 30 cm/s for sport diver certification* (and that can take **WEEKS** in the case of saturation divers).

What's the advantage to this, over just riding on a boat? You can get the same results by towing a balloon with a camera attached to it, without risking someones life. The only use I can see for it is for entertainment, like those parachute rides at the beach.

Under limited circumstances, that scheme can actually make some sense. The usual motivation for going hybrid, rather than electric, is that electric offers very limited range. Unfortunately, the gas engine adds weight. So, if you make the engine a modular extra, you can accept the added weight for long range use, and leave it in the garage for short runs about town.

It isn't clear that it is practical enough to overcome the inconvenience and oddity of the scheme; but it isn't pure nonsense.

Yeah, typical/. headline: so misleading that you have to read the article to figure out what they're talking about, and 90% of the discussion is focused on either annoyance about or misapprehension of the false headline.

There's a story below that has a headline about the odds of finding an Earth-like planet within a few dozen lightyears of Earth, but I'm pretty sure the actual story is about a new way to bake pastry. With a/. headline, why would anyone assume otherwise?

Yeah, typical kdawson headline: so misleading that you have to read the article to figure out what they're talking about, and 90% of the discussion is focused on either annoyance about or misapprehension of the false kdawson headline.
There's a kdawson story below that has a kdawson headline about the odds of finding an Earth-like planet within a few dozen lightyears of Earth, but I'm pretty sure the actual kdawson story is about a new way to bake pastry. With a kdawson headline, why would anyone assume ot

I would presume that it will be mostly used by as a theme park / tourist attraction / eXtreme sports thing. The $200k will be nothing compared to the wages, operating expenses, free t-shirts, and public liability insurance.

In America's Cup Yacgting they pull a crewman to the top of the mast to look out for wind gusts (or to make repairs in the rigging)

Heh. I have a friend who had built this 25m long 2 mast square-rigged sailboat [stmaarten-shoretrips.com] (I wonder if the new owner kept the 3 functionnal cannons), and we certainly did not need any excuse to go up the rigging... At any time, half the crew was always up there...

Ever see a parasailer? Like that, but for people who enjoy spraying mass quantities of water on whatever is below them.

Really stretching now, could be used from the deck of a ship to quickly access overhead unloading cranes... if attached to a submarine it could potentially be used for personnel transfer to helicopters... ummm... I think it's just slightly more useful than the jet-pack James Bond used in Thunderball.

Watch the video. The "boat" that is towed behind you is smaller than the typical jet-ski and it is tethered to you. You fly where you want to go and the "boat" follows you. It actually looks pretty cool.

What exactly are the advantages over just simply using a boat?

Think of this as an uber-cool SeaDoo. A SeaDoo has no advantages over a boat other than it's more fun to drive. Same with this thing.

As many others have pointed out, the name "jet pack" conveys entirely the wrong meaning. Jet packs are by implication untethered, with the "pack" containing everything required by the jet. So we need a more appropriate name to convey that the pack is tethered, and that the jet is pulling something on the end of its tether along.

Well the answer is obvious: this is a JET CART, because the jet takes the place of a horse and is pulling the cart (boat) along. Naturally the horse is tethered to the cart, and

And here is was, thinking that they had an actual jet pack. But this... this is just a useless toy. Hey - when I want to fly around in the city, a *hose* isn't exactly practical.

But this leads to some inherent problems with jetpacks and flying cars: fuel problems aside, these things would be *hard* to pilot. Just think about it - you're flying around with your shiny jetpack, at what, 150mph? Imagine the accidents that could happen, or the amount of skill necessary to remain in control of that thing. Same f

Same for flying cars. Just look at the number of *regular* car accidents. Adding an extra degree of freedom will not exactly lower down that number.

It looked fine in Back to the Future Part 2. How hard could it be? They had floating lane dividers and everything.
The only problem I can see is that it will add a whole new dimension to being "double-parked".

I think the whole "control" thing is what makes it a flying car as opposed to a plane.

You can already fly around the city at 150mph if you wanted to(and can get whatever permits are required) in a plane. Planes aren't even all that fuel inefficient.

The idea of a flying car is a vehicle that is as easy to control as a car(or easier), but which can fly. This is of course theoretically possible, but the lift system and power generation equipment has yet to be invented.

One of the earliest uses for balloons and large kites was to tow an elevated observer behind a ship. I guess navies will be extremely interested in this. It's much less visible than a helicopter, cheaper, and safer, yet it permits over-the-horizon observation. Think of pirates off Somalia. Currently they can easily see and avoid ships, but fast patrol boats can't see them beyond a few miles. With one of these a small intercept craft can see the pirates, while remaining almost invisible themselves. Think of it as a floating artillery OP and the uses are obvious.

Actually, no. You have the means mixed up with the purpose. The intended use for the balloons and the kites was to get them the f*** up in the air so that the people in them could make observations. Towing them behind ships was simply a means to do that.

This thing only goes up 50' high. Not very useful for observational purposes.

There are much easier ways to do this than pumping water 50 feet in the air, like say... a camera on a balloon? The only ships going after pirates are sufficiently large enough to carry a mast or helo with enough range that another 50 feet vertical wouldn't change.

In your case, you appear not to have understood the Somali problem - the use of small high speed RIBs that can outrun a ship, and will see the fixed mast of a ship at a range that makes it useless for pursuit. You need similar pursuit craft that can quickly put up a mobile OP, and as quickly drop it to avoid observation. Helicopters are expensive to run, probably just too expensive for anti-piracy, balloons cannot be deployed quickly and are themselves higher than the observation point so they can be detect

Somali pirates are armed. Some jackass flying around on a glorified pressure-washer is going to have AK rounds coming at him awfully fast.

A more effective tool for dealing with the Somali pirate problem would be small, cheap UAVs. This toy can get ALL the way up to 15 meters in the air? That's not "over the horizon". Even a small vessel like a frigate has a mast height much greater than 50 feet.

You're wrong because these days they can just use a quadrocopter or some other convenient ROV form factor and it would be a lot cheaper and more functional. It could be a great means of propelling subaquatic ROVs, though.

I can't believe you've got a +5 insightful mod for that ! This thing can reach a height of 15 metres, is that even at deck level on a Naval Frigate ? I can't see how it would be any use to the navy at all, they have 1001 more suitable tools for over the horizion spying than this several of which are cheaper, more reliable, safer, more effective and more useful.

It can't go anywhere a boat can't go. It can't go faster than a boat. It has no more range than a boat. But it carries significantly more danger than most boats ever did. It can go up as high as -- oh my gosh -- 15m... around 50 feet. And it has no payload capacity whatsoever.

So... what's it going to be used for? Rescuing cats from trees along the river?

One way you can account for an engine pump failure is to use pressurized tank. When the engine fails you have enough remaining pressure to bring the passenger down safely.

One concern of mine would be a control failure where nozzle control is lost, leading to a situation where the passenger may get injured. This could be accounted for in design, but is it cost-effective?

I would just hate to be the guy that has the first accident on this thing, slamming into something solid, or hitting the water fast enough t

Water is heavy stuff - you don't have to expel much of it at a mediocre velocity in order to support the weight of a adult human.

What made those portable jetpacks interesting is that they used a limited amount of reaction mass and managed to expel it with sufficient velocity that it was able to support the weight of the pilot+jetpack.

Personally, I would be satisfied to see a solution based upon small jet turbines with vectored thrust. In some ways, it would be more tricky to make stable due to the response

This sounds like a recreational device, and perhaps an interesting one. Calling it a "James Bond-style jet pack" is rather misleading, though.

Safety: a fall into water from that height is not safe but not suicidal. I wonder how bad it is to be underneath and accidentally get sprayed by one of those jets? The video clip is silent; I'll bet the thing makes a hell of a racket. I wonder how many waterfronts will put up with it.

I'm thinking, team sports. An extreme kind of polo or soccer or something. With players deliberately maneuvering to hit each other with the jets and/or tangle their hoses.

...idiotic contraption to make noise, and spoil the serenity of my local lake. Fricking manufacturers should be stopped from producing these things that serve no purpose other than to encourage stupid people to waste their money.

The same retards buy 500 hp speedboats to drive at 60 miles an hour on a mile long lake. Shit-for-brains people like that should be buried young.

Go and look up what a jet actually is. Here. Let me help you [wiktionary.org].

jet (plural jets)

1. A collimated stream, spurt or flow of liquid or gas from a pressurized container, an engine, etc.
2. A spout or nozzle for creating a jet of fluid.
3. A class of airplane using jet engines rather than propellors.4. An engine that propels a vehicle using a stream of fluid as propulsion.
5. A part of a carburetor that controls the amount of fuel mixed with the air.

Oh, sure, it sounds good, but what if the hoses rupture while you're being towed over the ocean-- that's straight water pouring out, at tens of gallons per second! It'll get all over everything! And what are the people running it going to do then, when there's suddenly water all around them? Float? Didn't anyone think this through?

This does sound seriously fun... and smart too. Shades of Armadillo's EPA visit for their earlier hydrogen peroxide rocket, paraphased "what do you do if there's a fuel spill"

Sure it looked fun, but my reaction was more like, "wouldn't it be easier to just ride in the boat?" And if the added feature is being able to gain elevation and move back and forth, well, a cherry-picker in a boat then. Without having to wear the propulsion system on you.

You're off the coast of Somalia. Pirates come at your vessel. You just smile, as 5 members of a special forces unit deploy. Skirting around 45 meters off the water with tactical weaponry, RPGs, and machine rifles.

Within moments the pirates have been decimated, the few remaining have turned and fled.

Oh the second article says they are 100,000 GBP, or $142,362.59 USD at todays rate, but the second article is older...they must have upped the price...oh wait the second one is fox news, nevermind its probably always been 130,000 GBP

The water direction reverses. Assuming that its exit velocity is the same as the pipe velocity (possibly incorrect) and that it has a mass transfer of M kg/s at a velocity of V M/s, the momentum change is 2MV per second. Conservation of momentum means that this must be transferred to the "pilot", which because of its direction must oppose the change in momentum the pilot must experience due to gravity. Tension in the pipe opposes any net difference between gravity and lift. If the pipe is blocked the liquid

I know; that was the point I was making. For every kg of water fired downwards as thrust another kg must be lifted, thus negating it. At least blocking the end so the pipe fills with water under pressure would give some actual, measurable degree of support.:-)